All leagues are different. I recommend adjusting them for your own league dynamics and settings -- add X points to quarterbacks if quarterbacks are in higher demand in your league; add Y points to wide receivers if you start 3 wide receivers. Margin of debate is +/- 1.5 points, so I would consider any trade within 3 points to be fair.

This is a beta experimental chart. Formulas are still being tweaked. It is extremely difficult to capture trade value across positions and for transactions involving 3 or more players. Players like Josh Gordon will have wildly different values for different teams and leagues.

Method. I start with Fantasypros rest of season rankings from highly accurate experts. Within a position, trade value is inversely proportional to average ranking. The list is then scaled based on 12 team roster depth so that borderline free agents are worth zero (since you can pick them up for free). Values are then passed through mean shifted logistic function, which gives higher value to the upper quintile. This is done to scale the values properly for 2-for-1 trades.